Oil shale and marlstone.
Drab sandstone, drab to variegated claystone and siltstone; locally derived conglomerate around basin margins. Lower part is Paleocene.
Greenish-gray, olive-drab, and white tuffaceous sandstone and claystone; lenticular marlstone and conglomerate.
Equivalent to, and lithologically similar to locally derived basin-margin conglomerate of Wasatch Formation; merges southward into main body of Wasatch Formation. Lower part is Paleocene.
Includes active and dormant sand dunes. In northwestern Wyoming is chiefly loess (age 12,000-19,000 years).
Gray, green, tan, and dull-red tuffaceous arkosic sandstone and claystone.
Clay, silt, sand, and gravel in flood plains, fans, terraces, and slopes.
Variegated claystone and lenticular sandstone; conglomeratic near south margin of Wind River Range.
(Northwest, Southwest, and Central Wyoming) - Brown to gray sandstone, gray to black shale, and thin coal beds. (East Wyoming) - Light-colored massive sandstone, drab shale, and thick coal beds.
Chiefly clay, silt, and fine sand. Includes travertine deposits.
Wilkins Peak Member - green, brown, and gray tuffaceous sandstone, shale, and marlstone; contains evaporites in subsurface sections. Tipton Shale Member or Tongue - oil shale and marlstone.
Rock Springs uplift. White to brown sandstone, shale, and claystone; numerous coal beds.
Oil shale and marlstone.
Rock Springs uplift. Drab-yellow and brown sandstone and sandy shale.
Gray to black soft sandy shale and shaly sandstone.
Rock Springs uplift. White and brown soft sandstone, gray sandy shale, coal, and carbonaceous shale.
Rock Springs uplift. White massive sandstone; lenticular chert-grit conglomerate in upper part.
Oil shale, carbonaceous shale, and sandstone.
Brown sandstone, carbonaceous shale, and coal.
Clasts of red quartzite, gray chert, and limestone in a gray to white tuffaceous sandstone matrix.
Green, brown, and gray tuffaceous sandstone, shale, and marlstone; contains evaporites in subsurface sections.
Southwest Wyoming: Southern Rock Springs uplift--Pale-green to tan tuffaceous sandstone and claystone of Miocene(?) age. Conglomerate of uncertain correlation locally at base. Saratoga Valley and west and southwest to Colorado--White massive soft tuffaceous sandstone and lesser amounts of white marl; lower part conglomeratic. Underlies North Park Formation in Saratoga Valley. To the west and southwest is called Browns Park Formation. Rawlins area--White massive soft tuffaceous sandstone; Central Wyoming: White soft tuffaceous sandstone. Locally derived conglomerate in upper and lower parts of sequence; in places lower conglomeratic sequence may be of Oligocene age. In Granite Mountains K/Ar age of tuff in lower part of sandstone sequence about 17 Ma and fission-track age of lower conglomerate about 24 Ma.
Mostly locally derived clasts. Includes some glacial deposits along east flank of Wind River Range. Locally includes some Tertiary gravels.
(North Wyoming) - Thick-bedded buff sandstone and drab to green shale; thin conglomerate lenses. (South and Northeast Wyoming) - Brown and gray sandstone and shale; thin coal and carbonaceous shale beds.
Fox Hills Sandstone (Kfh) - Light-colored sandstone and gray sandy shale containing marine fossils. Lewis Shale (Kle) - Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds.
Locally includes intermixed landslide and glacial deposits, talus, and rock-glacier deposits.
Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds.
Contains interbedded lithologies of Battle Spring (Tbs) and Wasatch (Tw2) Formations.
Leucite- and nepheline-rich flows, scoria, and necks.
White to pale-pink blocky tuffaceous claystone and lenticular arkosic conglomerate.
(Northern Yellowstone area) - Gray to brown shale and siltstone. (North and South Wyoming) - Dull-gray shale, gray siltstone, and fine-grained gray sandstone.
Mostly alluvium, colluvium, and glacial and landslide deposits. Primarily in Yellowstone area and Bighorn Mountains.
Partly consolidated gravel above and flanking some major streams.
Mesaverde Formation (north Wyoming) - Light-colored massive to thin-bedded sandstone, gray sandy shale, and coal beds. In Jackson Hole locally contains gold-bearing quartzite conglomerate. North of North Fork Powder River east of the Bighorn Mountains, consists solely of the Parkman Sandstone Member. Mesaverde Group (South Wyoming) - Includes Almond Formation, Ericson Sandstone, Rock Springs and Blair Formations in Rock Springs uplift; Almond Formation (white and brown soft sandstone, gray sandy shale, coal and carbonaceous shale), Pine Ridge Sandstone (light-gray sandstone and thin coal beds), and Allen Ridge (gray sandstone, shale, and thin coal beds) and Haystack Mountains (gray marine sandstone and shale) Formations in Rawlins uplift; Pine Ridge Sandstone (light-gray sandstone and thin coal beds) and Rock River Formation (soft sandstone and sandy shale) in Laramie Basin.
Reddish-brown conglomerate, chiefly of Paleozoic rock fragments.
Claystone and oil shale; in Sand Wash basin. In extreme northwest includes rocks of Wilkins Peak Member
Claystone, oil shale, and sandstone; in Sand Wash basin
Giant boulders of granite in arkosic sandstone matrix. Reynolds (1976) considers age of eastern exposures to be Oligocene(?).
Claystone, mudstone, and sandstone; in Sand Wash basin
Mudstone, sandstone, and carbonaceous shale; in Sand Wash basin
Claystone, shale, and sandstone
Sandstone and siltstone; west of Park Range